Aim: The purpose of this study was to compare the cyclic fatigue resistance WaveOne Gold and WaveOne files in a reciprocating motion. Materials and methods: A total of 24 new rotary WaveOne Gold (ISO size = 25, taper = 0.07, length = 25 mm) and WaveOne files (ISO size = 25, taper = 0.08, length = 25 mm) were selected and divided into 2 groups (n = 12 each). A cyclic fatigue-testing device was fabricated with a 90-degree angle of curvature and a 5 mm radius. All instruments were reciprocated until fracture occurred. The time was taken for each instrument to fracture, and the length of the broken fragments was recorded. All the fractured files were analyzed under a scanning electron microscope to detect the mode of fracture. The Kolmogorov–Smirnov test was used to assess the normality of sample distribution, and statistical analysis was performed using the independent sample t test. Results: The time taken for the instruments of WaveOne Gold group to fail under cyclic loading was significantly longer compared with the WaveOne group (p < 0.001). Scanning electron microscopic observations showed that the instruments of all groups had undergone a ductile mode of fracture. The length of the fractured segments was between 1.5 and 5 mm, which was statistically significant among the experimental groups. Conclusion: WaveOne Gold instruments showed a significantly higher cyclic fatigue resistance compared to WaveOne in a reciprocating motion.